Servicing Rights - Valuation allowance for impairment of residential mortgage servicing rights portfolio (Details) - Residential mortgage servicing rights $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)
Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward]
Valuation allowance, beginning of period	$ 10
Additions charged to operations, net	5
Valuation allowance, end of period	$ 15

Reflects the estimated amount of impairment as of the balance sheet date of recognized servicing assets that are being amortized in proportion to and over the period of estimated net servicing income or loss.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 4
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122739-111746

+ Details

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Period Type:	instant

- Definition

The net increase (decrease) in the valuation allowance for servicing assets subsequently measured using the amortization method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 4
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122739-111746

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Details

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